The present invention relates in general to timing and in particular to improved apparatus for providing repetitive timed events of predetermined duration that create a signal for indication of elapsed time, preferably within a mechanism attachable to a cap, such as for a medication container, for signaling the time for taking a medication therein.
The present invention has as an important object the provision of timing periods and signalling frequencies using a minimum of component size and complexity with minimal operating current and without the use of multiple oscillators or independent time-bases. This is accomplished by using a master CMOS Schmitt-trigger oscillator connected to chained CMOS logical flip-flops providing binary divided frequency/time-bases which are then connected to other CMOS logic to yield the final desired signal through a piezo effect audible transducer and/or a liquid crystal visual indicator.
Another important object of the invention is to latch the signalling device until deliberately reset by the operator. This is accomplished by connecting the final duration time base output to an R-S flip flop (latch) comprised of two dual input CMOS logical NOR gates.
Another important object of the invention is to provide an indication of battery readiness at the time of deliberate operator reset. This is accomplished by connecting an intermediate time base output to an R-S flip flop comprised of a pair of dual input CMOS logical NOR gates. The output of the signal latch flip flop and the battery readiness indicator flip flop are connected through diodes before coupling to prevent interaction.
It is a further object of the invention to achieve the foregoing object with reliably operating apparatus yielding repeatable output indications and virtually insensitive to all but the most severe variations in the battery supply.